A. Field of the Invention
This invention relates generally to vehicle movement, and in particular to an apparatus for moving a wheeled vehicle.
B. General Discussion
This invention was developed by us in response to a need which arose during production of the standard light rail vehicle being manufactured by the surface transportation systems group of the assignee company. The standard light rail vehicle is a mass transit tracked vehicle with an undercarriage which carries a coach or body. In the assembly of these vehicles a need arose for moving the undercarriages in particular, and even the assembled vehicle, between assembly stations. Moving these vehicles on the assembly-line, however, requires consideraable manpower, improvisation of available facilities and equipment, and removal and/or replacement of obstructions (work platforms, wiring connections, air lines, etc.) from the aisles to permit usage of equipment. All this substantially increases the man hours (beyond normal moving time) required to move the vehicles. The problem is complicated further by the fact that these vehicles weigh approximately 70,000 pounds, a significant portion of which is made up by the undercarriage.
We are aware of tow trucks used in the aviation industry for moving aircraft to, for example, a maintenance hangar. These tow trucks, however, are not suited for use on an assembly line because they must be kept in a remote area and transported to the assembly line. Even more importantly, however, is the fact that the space requirements on an assembly line simply preclude using these trucks.
We determined that the apparatus should be simple, compact, relatively light in weight, easy to install on and remove from the vehicle and easily managable for controlling movement of the vehicle.